CRYO NEEDLE GUIDE
A needle guidance assembly for constraining and guiding an interventional needle is provided. The needle guidance assembly includes a needle guide having opposing lever arms. Jaws of the opposing lever arms form a guide bore configured to receive an interventional needle and orient the needle with respect to, for example, an imaging probe. Constraining the needle within the imaging field of the probe allows for real-time monitoring during insertion of the interventional needle into patient tissue. In addition, the needle guidance assembly is angularly positionable relative to the image field to allow advancement of the needle to a target site within the imaging field.
The present application claims the benefit of the filing date of U.S. Provisional Application No. 62/744,849 having a filing date of Oct. 12, 2018, the entire contents of which is incorporated herein by reference.
FIELDThe present disclosure is directed to utilities (i.e., systems, methods and apparatuses) for guiding interventional needles during medical procedures. More particularly, the disclosure relates to utilities that allow for guiding and maintaining an interventional needle in a fixed relationship with a medical imaging instrument.
BACKGROUNDDoctors and other medical professionals often utilize medical imaging instruments to conduct non-invasive examinations. That is, medical imaging instruments, including X-ray, magnetic resonance (MR), computed tomography (CT), ultrasound, and various combinations of these instruments/techniques, are utilized to provide images of internal patient structure for diagnostic purposes as well as for interventional procedures. Such medical imaging instruments allow examination of internal tissue that is not readily examined during normal visual or tactile examination, which could then be used for either diagnosis (e.g. MRI for prostate) or for guidance to a region of interest in the body (e.g. interventional procedures like biopsies, therapy, etc.).
Medical imaging instruments typically allow for generating three-dimensional (“3D”) images of internal structures of interest, often by interleaving a series of 2D images. For instance, a medical imaging device may be utilized to generate a 3D model or map of the prostate such that one or more biopsies may be taken from certain desired locations of the prostate and/or therapy may be delivered to those desired locations of the prostate. For purposes of prostate imaging, a transrectal ultrasound-imaging device (TRUS) provides image acquisition and guidance. TRUS probe is the most widely accepted technique for prostate applications due to its simplicity, high specificity, and real time nature. In such an application, the TRUS probe or similar medical imaging device may be inserted into the rectum of a patient to generate one or more 2D images. Such images may be utilized to generate a 3D image of the prostate that may subsequently be utilized to take one or more biopsies from a prostate location of interest and/or apply therapy (e.g., implant radioactive seeds) at one or more desired locations.
For procedures that require precision, such as targeted biopsy and other treatment procedures, it is desirable that the relative location between an imaging instrument and an anatomical area of interest be known. That is, it is important that the image plane of a medical imaging instrument covers a particular tissue location and remains stationary to allow for guiding a biopsy/treatment device to that tissue location within the imaging field. Relative movement between the imaging device and the tissue area of interest during imaging and/or biopsy/treatment may impede the successful performance of these procedures. Accordingly, a number of holding and manipulating/positioning assemblies have been proposed wherein a holder interfaces with an imaging device such as a TRUS probe. The holder may be interconnected to one or more mechanical armatures and/or actuators such that the probe may be precisely controlled and mechanically positioned and/or rotated relative to an area of interest on a patient (a “tracking assembly”) to maintain a fixed position relative to the patient.
Similarly, it is critical for interventional procedures that the medical imaging instrument is also maintained in fixed relation to the interventional needle. In this regard, a needle guide may be affixed to the holder to direct the interventional needle to a desired location within the image plane of the probe. U.S. patent application Ser. No. 15/203,417 describes an embodiment of one such needle guide. However, such guides may be cumbersome and there remains a need for a needle guide that may be quickly deployed to simplify the process of introducing an interventional needle during a medical procedure.
SUMMARYProvided herein are utilities (i.e., apparatuses, systems and methods) that combine the positioning and support of a needle guidance assembly with respect to a medical imaging instrument (e.g., ultrasound probe) such that an interventional needle (e.g., therapy delivery device, biopsy needle, trocar, etc.) held by the needle guidance assembly, for insertion into patient tissue, is constrained within an imaging field of the medical imaging instrument. Constraining the biopsy treatment device within the imaging field allows for real-time monitoring of the biopsy/treatment device during insertion into patient tissue. In addition, the needle guidance assembly is angularly positionable relative to the imaging field to allow advancement of the interventional needle to any desired location within the imaging field. The interventional needle may be used to take biopsies and/or apply therapeutic matter such as, for example, brachytherapy seeds, cryoablation fluid (e.g., liquid or gas), ablation energy, and/or electroporation energy (electric field energy). In one arrangement, movement of the needle guidance assembly is limited to a single degree of freedom allowing angular positioning of an interventional needle within a two-dimensional image plane.
According to a first aspect, a needle guide for medical diagnoses and treatment includes first and second lever arms, a pivot pin, and a guide bore. The pivot pin may connect the first and second lever arms and define a pivot point therebetween. Each of the lever arms may include a jaw and a handle extending from the jaw on an opposing side of the pivot point. The first and second lever arms may have a closed configuration in which the jaws are in physical contact with one another and the handles are spaced apart. (e.g., by a maximum distance). The lever arms may also have an open configuration in which the jaws are spaced apart and the handles are spaced apart by less than the maximum distance. The guide bore may be configured to receive an interventional needle. The guide bore may be defined by the jaws when in the closed configuration.
In an embodiment, a first C-shaped channel along the length of the jaw of the first lever arm may mirror a corresponding second C-shaped channel along the length of the jaw of the second lever arm. In this regard, the first and second C-shaped channels may form the guide bore when in the closed configuration. The first and second C-shaped channels may be contiguous in the closed configuration and completely enclose the guide bore. Alternatively, at least a portion of the first and second C-shaped channels may be spaced apart in the closed configuration such that a portion of the guide bore is unenclosed by the first and second C-shaped channels.
In another embodiment, a needle guide may include an optional biasing mechanism configured to bias the first and second lever arms toward the closed configuration. Such a biasing mechanism may be a spring in compression disposed between the handle of the first lever arm and the handle of the second lever arm or may be a spring in tension disposed between the jaw of the first lever arm and the jaw of the second lever arm.
In yet another embodiment, a needle guide may include a mounting bracket. The first and second lever arms may be affixed to the mounting bracket. The mounting bracket may be configured for removable attachment to a base member of a system configured to hold a medical imaging instrument in pivotal relation to the base member. One or both lever arms may be affixed to the mounting bracket via the pivot pin.
In another aspect, a system for medical diagnoses and treatment may include a probe holder, an interventional needle, and a needle guidance assembly. The probe holder may be configured to hold a medical imaging instrument. The needle guidance assembly may include a base member and a needle guide. The base member may be pivotally attached to the probe holder for angular manipulation of the needle guidance assembly with respect to the medical imaging instrument. The needle guide may be removably attachable to the base member to retain the needle guide in fixed relation to the base member. The needle guide may include lever arms, a pivot pin, and a guide bore as described above. A trajectory axis of the guide bore may be aligned within an image plane of the medical imaging instrument when the medical imaging instrument is disposed within the probe holder.
The probe holder may generally form a recessed surface or cradle configured to receive and secure a portion of a medical imaging instrument. In such an arrangement, an acquisition portion (e.g., transducer array) of the medical imaging instrument is secured in a known relationship to the probe holder. The probe holder may include a rotatable coupling adapted for rotatable connection with a positioning device such that the probe holder and supported medical imaging instrument are operative to rotate about a rotational axis of the positioning device. The positioning device may include various encoders that output a 3D position and/or orientation of the attached probe holder and supported medical imaging instrument. As a fixed relation of an acquisition portion of the medical imaging instrument is known relative to the probe holder, the orientation of the acquisition portion is known in a 3D space of the positioning device. This allows for locating images from the medical imaging instrument in the known 3D space. In one arrangement, an acquisition axis of an ultrasound probe is aligned with the rotational axis of the positioning device.
In addition, the system includes a needle guidance assembly having a guide bore (e.g., needle guide bore) that may be aligned with an image plane of a medical imaging instrument when instrument is secured within a probe holder. Thus, the spatial relationship of the needle guidance assembly is known relative to the acquisition axis or imaging field of the medical imaging instrument. In this regard, a trajectory (e.g., needle trajectory) of the guide bore may be plotted on an output image of the medical imaging instrument. Thus, the medical imaging instrument may be rotated to display a desired portion of an anatomical internal structure having, for example, a target site (e.g., prostate lesion). An image (e.g., 2D image from the image plane of the instrument) including the target site may be generated on a display. Further, the trajectory of the guide bore (e.g., needle trajectory) may be superimposed on the image. To permit alignment of the guide bore trajectory (and subsequently the interventional needle) with the target site, the needle guidance assembly may rotate relative to the probe holder to adjust the guide bore trajectory within the image plane. Thus, the guide bore trajectory may be aligned with a target site within the image plane. Accordingly, a user may extend an interventional needle through the guide bore of the needle guidance assembly into the patient and ultimately to the target site. Such insertion may be executed while monitoring real-time imaging.
In an embodiment, a medical imaging instrument may be a side-fire ultrasound probe. The base member may rotate about a second axis that is transverse to an image plane of the ultrasound probe.
In some embodiments, the interventional needle may be a biopsy needle configured to extract tissue samples or may be configured to deposit or apply therapeutic matter. For example, therapeutic matter may include at least one of: brachytherapy seeds; a cryoablation fluid (e.g., liquid, gas, plasma etc.); ablation energy; and electroporation energy.
In another aspect, a method of administering treatment is provided. The method may include, inter alia, scanning a patient with a medical imaging instrument disposed in a probe holder; identifying a target site within tissue of the patient; aligning a guide bore of a needle guidance assembly with the target site, and extending an interventional needle through the guide bore into the patient tissue to the target site. The needle guidance assembly may be similar to that described above.
Reference will now be made to the accompanying drawings, which assist in illustrating the various pertinent features of the present disclosure. Although described primarily in conjunction with transrectal ultrasound imaging for prostate imaging, biopsy, and therapy, it should be expressly understood that aspects of the present disclosure may be applicable to other medical imaging applications. In this regard, the following description is presented for purposes of illustration and should not be considered as limiting the scope of the invention.
Utilities are disclosed that facilitate obtaining medical images and/or performing medical procedures. One embodiment provides a combined medical imaging instrument holder (e.g., probe holder) and a needle guidance assembly. The needle guidance assembly maintains a trajectory of a supported interventional needle (that term is used herein to generally refer to any elongated medical device needing precise guidance, e.g., needle, trocar, therapy device, etc.), which is configured for insertion into patient tissue. The needle guide of the needle guidance assembly may be used independently, may be used with a base member for stabilizing the needle guide, or may be used with a probe holder to restrain the trajectory of the needle within an imaging field of a medical imaging instrument (e.g., two-dimensional image plane of an ultrasound probe) held by the probe holder. The probe holder may be configured for rotational attachment with a positioning device allowing the location of the medical imaging instrument and its image plane to be known in a 3D space. The positional relationship between the probe holder and the needle guidance assembly may be maintained while the probe holder is rotated. In this regard, the medical imaging instrument supported by a probe holder may obtain multiple 2D or 3D images of patient's anatomy in different orientations. The attached needle guidance assembly may be utilized to direct an interventional needle through the patient's tissue to a target site within an image plane of the medical imaging instrument. For example, a biopsy needle may be directed through the guide bore of a needle guidance assembly, through a patient's perineum, and into the patient's prostate to extract a tissue sample. As the trajectory of the needle is aligned within the image plane of the medical imaging instrument, the progression of the biopsy needle may be displayed on a real-time image of the imaging device such that targeting may be performed under real-time image guidance.
As shown in
To achieve such fixed positioning of probe 10, it is desirable to interface the probe 10 with a positioning device such as the exemplary positioning device 100 shown in
When attached to the positioning device 100, the probe handle is held by an arm of the positioning device having set of position sensors. These position sensors are connected to the computer of the imaging system via an embedded system interface. Hence, the computer has real-time information of the location and orientation of the probe 10 in reference to a unified rectangular or Cartesian (x, y, z) coordinate system. With the dimensions of the probe 10 taken into the calculations, the 3D orientations of the 2D image planes are known. The ultrasound probe 10 can send signals to the imaging system 8, which may be connected to the same computer (e.g., via a video image grabber) as the output of the position sensors. The imaging system therefore can generate real-time 2D images of the scanning area in memory. The image coordinate system and the arm coordinate system are unified by a transformation. Using the acquired 2D images, a prostate surface (e.g., 3D model of the organ) may be generated and displayed on a display screen in real-time.
The computer system runs application software and computer programs which can be used to control the system components, provide user interface, and provide the features of the imaging system. The software may be originally provided on computer-readable media, such as compact disks (CDs), magnetic tape, or other mass storage medium. Alternatively, the software may be downloaded from electronic links such as a host or vendor website. The software is installed onto the computer system hard drive and/or electronic memory and is accessed and controlled by the computer's operating system. Software updates may also be electronically available on mass storage media or downloadable from the host or vendor website. The software represents a computer program product usable with a programmable computer processor having computer-readable program code embodied therein. The software contains one or more programming modules, subroutines, computer links, and compilations of executable code, which perform at least some of the functions of the imaging system 8. The user may interact with the software via keyboard, mouse, voice recognition, and other user-interface devices (e.g., user I/O devices) connected to the computer system.
The 2D and/or 3D images may be used to plan for certain interventional procedures in which accuracy and/or precision is necessary to pinpoint a target site (e.g., biopsy, brachytherapy, cryo-ablation, etc.).
Turning to
The utilities disclosed herein overcome the limitations of prior ultrasound guided biopsy and therapy systems by providing a combined probe holder for supporting a medical imaging instrument and needle guidance assembly that maintains a trajectory of an interventional needle held by the needle guidance assembly in a known positional relationship. Moreover, the known positional relationship may include an image plane of the medical imaging instrument held by a cradle of the probe holder. In this regard, the needle guidance assembly may be utilized, for example, to direct an interventional needle through a patient's perineum into the prostate to a target location while guided by a real-time display from the probe.
A biasing mechanism 95 may be used to bias the lever arms toward the closed configuration illustrated. Although illustrated as a coiled compression spring between the handles 94a, 94b, a biasing mechanism may additionally or alternatively include a tension spring, for example, disposed between the jaws 92a, 92b or may include a lever spring disposed adjacent to or around the pivot pin 97. Needle guide 91 may further include a mounting bracket 96 for associating the needle guide 91 with a base member of a needle guidance assembly or other device. In the illustrated embodiment, the mounting bracket 96 includes a generally U-shaped saddle configured to engage a base member and may include protrusions (not shown) from an inner surface of the saddle to engage corresponding recesses or grooves of the base member.
In the illustrated embodiment, the cradle 30 includes probe holder 40 having a recessed socket 42 that is sized to receive a handle portion 16 of the probe 10. Once the handle 16 of the probe 10 is located in the socket 42, the acquisition end 14 of the probe 10 extends beyond the distal end of the cradle 30 such that it may be inserted into a rectum of a patient. In the illustrated embodiment, the probe holder 40 includes a hinged clamp 44 that is connected to a first lateral edge of the recessed socket 42 via a plurality of mating knuckles 46, 47. A hinge pin (not shown) extends though these knuckles 46, 47. An opposing edge of the clamp 44 includes a latch (not shown) that allows for fixed attachment to an opposing later edge of the socket 42. In use, the clamp 44 is rotated open such that the handle 16 may be disposed within the socket 42. The clamp 44 may be rotated to a closed position and secured. This, in turn, secures the probe 10 within the socket 42 (see
The socket 42 is a recessed surface that, in the present embodiment, is correspondingly shaped to the handle portion 16 of the ultrasound probe 10 such that the probe 10 may be disposed within the socket 42. Ultrasound probes from different OEMs may have differing shapes. In this regard, the socket 42 may include a deformable lining that allows for engaging differently configured probes. Alternatively, different sockets may be utilized for different probes. That is, the socket 42 may be removably connected (e.g., via bolts or screws) to the cradle 30 to allow matching a particular socket to a particular probe. In any arrangement, the acquisition axis A-A′ of the probe 10 may be aligned with a rotational axis C-C′ of the positioning device. See
In addition to supporting probe holder 40, the cradle 30 also includes a needle guidance assembly 50 comprising a base member 54 and needle guide 91, which in the illustrated embodiment is fixedly connected to the clamp 44 which maintains the probe 10 within the socket 42. The needle guidance assembly 50 may be attached to other locations of the cradle 30 in other embodiments. As shown, the needle guidance assembly 50 is connected to an upper portion of the clamp 44 via an axle or spindle 52. The spindle 52 is received within a journal formed in the clamp 44. The spindle 52 also connects to an internal journal (not shown) in base member 54 of the needle guidance assembly 50. The spindle 52 permits the base member 54 of the needle guidance assembly 50 to rotate angularly relative to the probe holder 40 and supported probe 10. In one embodiment, the needle guidance assembly 50 rotates about an axis (e.g., center of spindle 52) that is transverse to an image plane of the probe 10 and/or the rotational axis of the positioning device. In such an embodiment, movement of the needle guidance assembly 50 and guide bore 58 is limited to one-degree of freedom within the image plane. Though discussed as using a spindle and journal, any hinged connection between the needle guidance assembly 50 and probe holder 40 may be utilized.
Removably connected to the base member 54 is a needle guide 91. The guide bore 58 of the needle guide 91 is sized to receive an interventional needle such that the interventional needle may selectively extend through the needle guidance assembly 50. The guide bore 58 of the needle guide 91 may be designed to accommodate various gauges of interventional needles. Alternatively, the needle guide 91 may be exchanged for other sized of needle guides to accommodate various interventional needles. In any case, an interventional needle may be extended through a distal forward surface of the needle guidance assembly 50.
The cradle 30 is designed such that the axis defined by the guide bore 58 of the needle guidance assembly 50 is aligned with the image plane of the supported probe 10. For instance, when a side fire ultrasound probe is utilized, an interventional needle extending through the guide bore 58 will extend into the image plane 20 of the ultrasound probe 10. That is, an axis or trajectory of the guide bore 58 is aligned within the image plane of the probe 10 as illustrated by the projection and front profile of the forward ends of the needle guidance assembly 50 and probe 10 in
Referring to
During use for a prostate procedure, the ultrasound probe 10 may generate an image 22 including a representation of a patient's prostate 70. Further, due to the use of the encoders 62 between the base member 54 of the needle guidance assembly 50 and the probe holder 40, a needle trajectory 80 corresponding with an axis of the guide bore 58 may be calculated and displayed on the ultrasound image 22. That is, the known orientation of the needle guidance assembly 50 relative to the image plane of the ultrasound probe 10 allows for determining where an interventional needle extending through the guide bore 58 of the needle guidance assembly 50 will protrude into the image 22.
If there is a desired target site 72 within the image 22 (e.g., within the representation of a patient's prostate 70), the angular orientation Θ of the needle guidance assembly 50 may be adjusted about the spindle until the needle trajectory 80 intersects the target site 72 (as in
In summary, the utilities disclosed herein allow for quick and safe placement of an interventional needle within a needle guidance assembly to facilitate real-time image guidance to targeted sites within an internal anatomical structure such as a patient's prostate. As a probe and needle guidance assembly are operative to co-rotate, any location within the anatomical structure may be imaged and targeted. Further, the ability to adjust the angular position of the needle guidance assembly within the plane of the ultrasound transducer likewise allows for targeting any location within the field of view of the imaging device.
The foregoing description of the present invention has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, and skill and knowledge of the relevant art, are within the scope of the present invention. The embodiments described above are further intended to explain best modes known of practicing the invention and to enable others skilled in the art to utilize the invention in similar or other embodiments and with various modifications required by the particular application(s) or use(s) of the present invention. It is intended that the appended claims be construed to include alternative embodiments to the extent permitted by the prior art.
Claims
1. A needle guide for medical diagnoses and treatment, comprising:
- first and second lever arms;
- a pivot pin connecting the first and second lever arms and defining a pivot point between the first and second lever arms, wherein each of the first and second lever arms include a jaw and a handle extending from the jaw on an opposing side of the pivot point, wherein the first and second lever arms have a closed configuration in which the jaws are in physical contact and the handles are spaced apart by a maximum distance and an open configuration in which the jaws are spaced apart and the handles are spaced apart by less than the maximum distance; and
- a guide bore configured to receive an interventional needle, wherein the guide bore is defined by the jaws when in the closed configuration.
2. The needle guide of claim 1, wherein the first lever arm includes a first recessed channel along the length of the jaw of the first lever arm and the second lever arm includes a second recessed channel along the length of the jaw of the second lever arm, wherein the first and second recessed channels form the guide bore when in the closed configuration.
3. The needle guide of claim 2, wherein the first and second recessed channels are contiguous in the closed configuration and completely enclose the guide bore.
4. The needle guide of claim 2, wherein at least a portion of the first and second recessed channels are spaced apart in the closed configuration such that a portion of the guide bore is unenclosed by the first and second recessed channels.
5. The needle guide of claim 1, further comprising:
- a biasing mechanism configured to bias the first and second lever arms toward the closed configuration.
6. The needle guide of claim 2, wherein the biasing mechanism comprises a spring in compression disposed between the handle of the first lever arm and the handle of the second lever arm.
7. The needle guide of claim 6, wherein the biasing mechanism comprises a spring in tension disposed between the jaw of the first lever arm and the jaw of the second lever arm.
8. The needle guide of claim 1, further comprising:
- a mounting bracket, wherein the first and second lever arms are affixed to the mounting bracket, and wherein the mounting bracket is configured for removable attachment to a base member of a system configured to hold a medical imaging instrument in pivotal relation to the base member.
9. The needle guide of claim 8, wherein at least one of the first and second lever arms is affixed to the mounting bracket via the pivot pin.
10. A system for medical diagnoses and treatment, comprising:
- a probe holder configured to hold a medical imaging instrument;
- an interventional needle; and
- a needle guidance assembly, the needle guidance assembly comprising: a base member pivotally attached to the probe holder for angular manipulation of the needle guidance assembly with respect to the medical imaging instrument; and a needle guide, wherein the needle guide is removably attachable to the base member to retain the needle guide in fixed relation to the base member, the needle guide comprising: first and second lever arms; a pivot pin connecting the first and second lever arms and defining a pivot point between the first and second lever arms, wherein each of the first and second lever arms include a jaw and a handle extending from the jaw on an opposing side of the pivot point, wherein the first and second lever arms have a closed configuration in which the jaws are in physical contact and the handles are spaced apart by a maximum distance and an open configuration in which the jaws are spaced apart and the handles are spaced apart by less than the maximum distance; and a guide bore configured to receive the interventional needle, wherein a trajectory axis of the guide bore is aligned within an image plane of the medical imaging instrument when the medical imaging instrument is disposed within the probe holder, wherein the guide bore is defined by the jaws when in the closed configuration.
11. The system of claim 10, wherein the medical imaging instrument is a side-fire ultrasound probe.
12. The system of claim 10, wherein the base member rotates about a second axis that is transverse to an image plane of the ultrasound probe.
13. The system of claim 10, wherein the interventional needle is a biopsy needle configured to extract tissue samples.
14. The system of claim 10, wherein the interventional needle is configured to deposit or apply therapeutic matter.
15. The system of claim 14, wherein the therapeutic matter comprises at least one of:
- brachytherapy seeds;
- a cryoablation fluid;
- ablation energy; and
- electroporation energy.
16. A method of administering treatment, comprising:
- scanning a patient with a medical imaging instrument disposed in a probe holder;
- identifying a target site within tissue of the patient;
- aligning a guide bore of a needle guidance assembly with the target site, wherein the needle guidance assembly comprises: a base member pivotally attached to the probe holder for angular manipulation of the needle guidance assembly with respect to the medical imaging instrument; and a needle guide, wherein the needle guide is removably attachable to the base member to retain the needle guide in fixed relation to the base member, the needle guide comprising: first and second lever arms; a pivot pin connecting the first and second lever arms and defining a pivot point between the first and second lever arms, wherein each of the first and second lever arms include a jaw and a handle extending from the jaw on an opposing side of the pivot point, wherein the first and second lever arms have a closed configuration in which the jaws are in physical contact and the handles are spaced apart by a maximum distance and an open configuration in which the jaws are spaced apart and the handles are spaced apart by less than the maximum distance; and the guide bore, wherein the guide bore is defined by the jaws when in the closed configuration; and
- extending an interventional needle through the guide bore into the patient tissue to the target site.
17. The system of claim 16, wherein the interventional needle is a biopsy needle configured to extract tissue samples.
18. The system of claim 16, wherein the interventional needle is configured to deposit or apply therapeutic matter.
19. The system of claim 18, wherein the therapeutic matter comprises at least one of:
- brachytherapy seeds;
- a cryoablation fluid;
- ablation energy; and
- electroporation energy.
Type: Application
Filed: Oct 11, 2019
Publication Date: Apr 16, 2020
Inventors: PABLO MEDINA (Marysville, CA), RAJESH VENKATARAMAN (ROCKLIN, CA), BRADLEY MARTINEZ (SACRAMENTO, CA), YANG XU (NEVADA CITY, CA)
Application Number: 16/599,938